I use godaddy's quick shopping cart for my store at http://markerkits.com
It works pretty well. It has a basic inventory control system, lets you schedule sales, and offers both UPS and USPS shipping. PayPal is integrated into the system and they do have a program to accept credit cards. They also have applications for Froogle data feeds and listing items on Ebay. Everything is done by templates and there is no need to hand-code anything. The even offer a variety of sales reports.

There are a few drawbacks, the biggest being that their shipping is limited to US addresses. The custom weight-based shipping front-end is limited to 10 different weight ranges. That makes things tough if you want to ship by first-class mail and have a wide range of product weights.

OSCommerce may be a bit overkill, but it's a free shopping cart, very flexible and works pretty well. You can integrate your paypal account with it easily, have inventory levels and all sorts of things...

If you're looking for something simple, why not just create the item for sale using paypal, put the picture and "buy now" link on a website? May be all you need..

Paypal is really a simple solution. For occassional items, the give a good rate. And many people are very familiar with it. When I used it, I found their online manuals and tech support to be very helpful. I'm pretty sure they have a decent, easy to use shopping cart setup as well. Best part is the credit card processing fees and system are all included. No worries about setting any of that up.

Anything more complex and you'll probably have to set up a merchant account for credit card processing. That means monthly minimums, and all that.

I switched from Paypal to my own system a couple years ago to get more control. Set up a merchant account with Chase Manhattan. They had good competitive rates, and nice software support -- it was pretty easy to download their PHP script and integrate it into my own shopping cart code.